Tuesday, January 1, 2013

New paper finds climate responds to short and long-term changes in solar activity

A new paper published in The Holocene finds a significant link between solar activity and climate over the past 1000 years. According to the authors, "Our results suggest that the climate responds to both the 11 yr solar cycle and to long-term changes in solar activity and in particular solar minima." The authors also find "a link between the 11 yr solar cycle and summer precipitation variability since around 1960" and that "Solar minima are in this period associated with minima in summer precipitation, whereas the amount of summer precipitation increases during periods with higher solar activity."

IRBSi is the proxy for precipitation/climate change and shows good agreement with solar activity. Figure 12. The comparison between the graphs of the IR-BSi and that of the solar cycles shows good agreement between the percentage of mineral materials of allochthonous and solar cycles reconstructed on the basis of changes in concentrations of 14 C in macrofossils.A good agreement is also evident between the concentrations of 18 O of foraminifera in the Norwegian Sea and the index IR-BSi.

Abstract

We report on a sediment record from a small lake within the subarctic wetland complex Stordalen in northernmost Sweden covering the last 1000 years. Variations in the content of minerogenic material are found to follow reconstructed variations in the activity of the Sun between the 13th and 18th centuries. Periods of low solar activity are associated with minima in minerogenic material and vice versa. A comparison between the sunspot cycle and a long instrumental series of summer precipitation further reveals a link between the 11 yr solar cycle and summer precipitation variability since around 1960. Solar minima are in this period associated with minima in summer precipitation, whereas the amount of summer precipitation increases during periods with higher solar activity. Our results suggest that the climate responds to both the 11 yr solar cycle and to long-term changes in solar activity and in particular solar minima, causing dry conditions with resulting decreased runoff.